A full-length infectious clone of beet soil-borne virus indicates the dispensability of the RNA-2 for virus survival in planta and symptom expression on Chenopodium quinoa leaves.

For a better understanding of the functionality and pathogenicity of beet soil-borne virus (BSBV), full-length cDNA clones have been constructed for the three genomic RNAs. With the aim of assessing their effectiveness and relative contribution to the virus housekeeping functions, transcripts were inoculated on Chenopodium quinoa and Beta macrocarpa leaves using five genome combinations. Both RNAs-1 (putative replicase) and -3 (putative movement proteins) proved to be essential for virus replication in planta and symptom production on C.

The beet virus Q coat protein readthrough domain is longer than previously reported, with two transmembrane domains.

Ten beet virus Q (BVQ) strains from six different countries were sequenced to characterize the readthrough (RT) domain of the coat protein (CP). The GenBank/EMBL/DDBJ accession numbers for the sequences reported in this paper are FM244643-FM244652. With three nucleotide additions of 5, 285 and 1 nt, the common RT of 76 kDa was found to be longer than the single reference available to date (35 kDa).